Electronic Tongue Knows Beer Better Than You

An "electronic tongue" developed in Spain that can accurately distinguish between four styles of lager beer every time.

"It's just a bunch of wires and buttons and computers," said María Luz Rodríguez-Méndez, a professor of inorganic chemistry at University of Valladolid in Spain. "It's an ugly thing full of cables."

However it looks, Méndez and colleagues developed an electronic tongue that accurately distinguished between four styles of lager beer 100 percent of the time. A variety of screen-printed sensors "taste" electrochemical compounds in the beer to predict the brews' color index and alcoholic strength 76 percent and 86 percent of the time. The new robot taster contributes to a growing field of electronic tongue and nose development meant to improve quality control in the food industry.

The researchers taught the software to recognize the signal patterns for each of the four lager styles. Like our brain, the computer can then compare new beer samples against the established, learned signal patterns. They tested each of the 25 beer samples seven times.

Many existing tongues using an array of sensors only get one data point for each sensor, said Méndez.

"But we have curves for each sensor."

The non-specific electrodes are responsible for their wealth of data. The phenols and electrodes send electrochemical signals to the computer as they interact. The researchers immerse the electrodes in beer and track the electrochemical signals as they turn up the voltage, said Méndez. Each sensor makes distinct electrical patterns because each is made from a different material. After analyzing the data with two pattern-recognition models, the electronic tongue was able to place the commercial beer sample into the correct lager category with 100 percent accuracy. It also predicted the beer's color with 76 percent accuracy, and its alcohol content with 84 percent accuracy.

In his 1943 short story Robinc, Anthony Boucher describes a cooking robot that was able to (of course!) taste the food under preparation:

Half your time in cooking is wasted reaching around for what you need next. We can build in a lot of that stuff. For instance, one [mechanical] tentacle can be a registering thermometer...

And best of all - why the nuisance of bringing food to the mouth to taste? Install taste buds in the end of one tentacle.
(Read more about Boucher's robot taste buds)